Quick disconnect means with electrically heated pitot tube



June 2, 1-970 J, MEJEAN ETAL 3,514,999

QUICK DISCONNECT MEANS WITH ELECTRICALLY HEATED PITOT TUBE Filed Feb. 19, 1968 Figure 3 IN VEN 7'0 RS: Jacques 6. Mejean Halsey 0. 8099 Henry B. K/af/e ATTO United States Patent 3,514,999 QUICK DISCONNECT MEANS WITH ELECTRI- CALLY HEATED PITOT TUBE Jacques G. Mejean, Greenwich, and Halsey 0. Bagg, Riverside, Conn., and Henry B. Klatte, Yonkers, N.Y., assignors to Universal Oil Products Company, Des Plaines, Ill., a corporation of Delaware Filed Feb. 19, 1968, Ser. No. 706,501

Int. Cl. G01n 1/00 U.S. Cl. 73-212 3 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an improved means for effecting a connection of an electrically heated Pitot tube to a base or mounting section on an aircraft or other desired location. More particularly the invention provides for alignment means as well as improved plug and socket means between bayonet and base sections so as to provide electrical current and air pressure transmission between such sections.

It is, of course, realized that electrically heated bayonet sections for Pitot tubes are not new and that various forms of mounting means have been used for complete Pitot tube assemblies. However, certain of the prior art devices have involved rather complex and expensive constructions or have had operational difficulties.

It is thus a principal object of the present invention to provide a simplified form of quick-connection type of assembly that can still efiect an efiicient transmission of the electrical current for heating the bayonet section and for conducting the air stream pressure to a tube connector.

A still further object of the present invention is to provide a quick disconnect and alignment system for mounting a Pitot tube where no special tools will be required in effecting either the mounting or disconnection steps.

Broadly, the present invention provides an electrically heated Pitot tube assembly including a mounting section permitting a quick disconnection with the outer bayonet section, which comprises in combination, an air intake Pitot tube section with an internal electrical heating coil therein, a cone section between the upstream end of the Pitot tube section and an end cover plate, a centrally placed open air tube through said end plate and external insulfator means around said air tube, a pair of electrical contact points on the periphery of said insulator means and electric wires through said cover plate from said contact points to said heating coil in said Pitot tube, a plurality of spaced apart and projecting L-shaped legs from the outer face of said end cover plate adapted to provide a rapid engagement with a separate mounting section in turn adapted to be connected to a vehicle body, said mounting section having spaced cut-out portions and adjacent lip portions whereby to receive and hold said projecting legs from said end cover plate of said Pitot tube section, a central air tube socket means mounted across the mid portion of said mounting section with an external tube connector means therefrom, and a pair of electric terminals in said socket means positioned to be in alignment and contact with said pair of electric contact points on said insulator means around the air tube from said Pitot tube section.

In a preferred embodiment a spring actuated pin is provided to extend outwardly from the face of the fixed mounting or base section such that the pin may project into a hole provided in the end cover plate or flange portion of the Pitot or bayonet section. Thus, by the proper orientation of the spring actuated pin unit and the hole positioned in the outer bayonet section, there can be maintained proper alignment between the two sections and the insurance that the internal electrical terminals will be in proper contact to provide electrical conduction to the heating coil and the bayonet section. In effecting the disconnect operation, it is merely necessary to push in the spring actuated pin with a small screw driver or dowel pin and simultaneously elfect a suitable turn of the bayonet section until there is a disengagement of the locking efiect between the bayonet and base sections. It is a particular feature of the present invention to provide a design which eliminates the need of any special tool in elfecting either the connection or the disengagement of the two sections of the Pitot tube assembly, although in the present embodiment, a small screw driver, rod, or readily available pin-like member would be necessary to effect the pushing-in and disengagement of the pin from the recess or hole in the flange portion of the removable Pitot tube section in order to permit its turning with respect to the fixed base or mounting section.

Additional features and advantages of the improved design of the simplified quick-disconnect type Pitot tube assembly will be apparent with reference to the accompanying drawing and the following description thereof.

Description of the drawing FIG. 1 of the drawing is a sectional elevational view through both the outer Pitot tube section and the fixed base section, in a non-engaged relationship.

FIG. 2 of the drawing shows an elevational view of the face of the mounting or base section of the assembly, as indicated by the line 22 in FIG. 1.

FIG. 3 indicates in a sectional view, one design of a spring actuated spring member which may be utilized as a part of the base or mounting section to provide spring actuated projecting pin for engagement and alignment purposes with a hole in the flange of the bayonet section.

Referring now particularly to FIGS. 1 and 2 of the drawing, there is indicated an outer Pitot tube or bayonet section 1 which has a small diameter bayonet portion 2 with air intake opening 3. As is well known in aeronautics or in connection with those familar with measuring air speed, the Pitot tube uses a small diameter intake section suitable for transmitting an air stream impact pressure, so as to permit comparison with static pressure and in turn provide a measurement of speed. In this case inlet 3 carries the air stream through a small diameter tubular passageway 4 into a larger passageway 5 which in turn discharges into the large internal zone 6 which communicates with a small transmitting tube 7. The inlet passageways 4 and 5 are indicated as being electrically heated by coil means 8 which in turn is supplied with electric current by way of lines 9 and 10. In this instance, the bayonet section 2 is shown as being of a separately fabricated tubular portion adapted to slip-fit or screw into the end portion of the cone-like or main body section 11. This latter section is, in turn, provided with a flange portion 12 adapted to abut the aircraft body section and conform with the periphery of a mounting section or base section 13.

Generally, the flanged section 12 will normally be of a circular shape, although it may be oval or elliptical, and is fabricated to conform with the peripheral configuration of the opposing base plate portion 14 of mounting section 13 after the segmented screw assembly of the two separate sections. The face of the outer bayonet section 1, across the interior of the flange portion 12, is enclosed with a suitable cover plate section 15 which in turn has spaced projecting L-shaped flange or leg portions 16. The latter do not continue for a full 360 but are spaced to provide at least two projecting leg portions and are sized to, in turn, fit into slotted portions in the face of plate section 14 on mounting section 13. In other words, as best shown in FIG. 2 of the drawing, the base plate section 14 has alternating projecting lip portions 17 and cut out portions 18 whereby the L-shaped projecting sections 16 may fit into the slot portions 18. In this embodiment four leg portions 16 upon being turned 45 will effect full engagement with the projecting lip portions 17 in the manner of typical segmented screw construction. The thickness or spacing of a slot portion 19 in leg sections 16 will be adjusted to accommodate the thickness of the plate 14 whereby the Lportions 16 may readily pass over and bear against the inside faces of lips 17 on mounting section 13.

As best shown in FIG. 1, within the central or mid portion of the cover plate 15 and around tube 7 there is an outer insulating member 20. The latter is in turn provided with a central passageway 21 so as to permit the continued passage of the air stream from the bayonet section through insulator portion and into the base section 13. Section 20 may be riveted, bolted or otherwise attached to plate member 15 so as to provide an air tight assembly between the two separate portions. As will be noted in the present embodiment, insulator 20, is pro- 'vided with a hub section 22 sized to slip fit into recess portion 23 of socket section 24 in base section 13. The outer face of insulator portion 22 is provided with two spaced apart terminals 25 which respectively connect to electric wires 9 and 10 carrying through the interior section 6 to coil means 8. Also, an outer tip section 26 is provided with an O-ring seal member 27 so as to effect a slip fit into a deeper recessed section 28 within the interior of socket portion 24. This arrangement transmits the air stream intake pressure from tube 7 and passageway 21 into a tube member 29, having a passageway 30, at the downstream end of base section 13 whereby the air stream pressure can in turn be transmitted into a suitable tube or conduit member connectable to the base section 13 at threaded coupling 31.

In order to provide electric current transmission between the two separable sections 1 and 13, there is indicated current conducting wires 32 and 33 passing through an insulator 34 to spaced terminals 35. As best shown in FIG. 2, the spaced terminals 35 on the inside face of section 23 are along one segmental portion of the latter in order to provide contact with terminals 25 on the Pitot tube section 1. The spacing of terminals 25 should, of course, be the same as between terminals 35 in order to be brought into proper alignment when section 1 is tightened and locked with the mounting section 13. The entire socket section 24 along with tube connector section 31 is shown supported from an inverted U-shaped strap section 36 which is indicated as being riveted or bolted to the base plate section 14. It is to be realized that the depth of the strap section 36 and the positioning of the socket section 24 therein shall be adjusted so as to provide proper alignment with the projecting insulator sections 22 and 26 of the Pitot tube section 1 after the latter has been brought into engagement with the mounting section 13. In order to have a good tight seal or contact between the two separable sections, a resilient gasket, such as O-ring 37, is provided on the outer face of the plate member 15 encompassing the projecting L-shaped leg sections 16.

Also, in order to insure the proper alignment between the external bayonet section 1 and the base or mounting section 13, as well as preclude turning with respect to such two sections after there has been the segmental screw engagement of such sections, a suitable pin member 38 is provided to project outwardly from base plate 14. This pin member serves to engage a suitable hole or recess in the flange portion 12 of the outer Pitot tube section 1. As best shown in FIG. 3 of the drawing, a lock pin on dowellike member 38 projects through an opening 39 in the face of base plate member 14 and is constantly urged outwardly by being biased from spring 41 acting against an internal larger diameter base portion 40. The spring 41 is shown as being encased in a small housing 42 suitably attached to the inside face of the base plate 14. As noted hereinbefore, upon the engagement of the two separate sections 1 and 13 the projecting pin portion 48 will slide around the face of flange section 12 of bayonet portion 1 until such time as there is the proper alignment to have pin member 38 fall into a hole properly oriented in flange 12. Conversely, when it is desired to effect the disconnection between the two separate sections, a dowel rod, awe, or small screw driver it utilized to push in the pin 38, against the action of spring 41, so that it does not extend into flange section 12 and the latter can be turned along with section 1. The latter is turned 45 in this embodiment so that L-shaped leg sections 16 will align with slots or cut-out portions 18 in base plate 14 to permit the outward pulling away of Pitot tube section 1 from the entire mounting section 13.

Although the present drawing indicates four lip sections 17 and four slot portions 18 to in turn accommodate four L-shaped legs 16 from bayonet section 1, it is entirely possible to utilize a lesser number of clamping sections or a greater number thereof in a typical segmented screw construction so that there may be the desired quick connection and disengagement of separate parts. Still other modifications in detail may be made within the scope of the present invention, as for example with respect to the size and configurations of the tube and socket portions of insulator means 20 and 24.

It is, however, a particular feature of the improved construction and assembly of this invention to have the quick segmental screw engagement in combination with a spring actuated locking pin from the mounting section whereby the assembly cannot be disengaged until such time as a rod or pin is used to effect the pushing in of the spring biased lock pin 38.

We claim as our invention:

1. An electrically heated Pitot tube assembly including a mounting section permitting a quick disconnection with the outer bayonet section, which comprises in combination, an air intake Pitot tube section with an internal electrical heating coil therein, a cone section between the upstream end of the Pitot tube section and an end cover plate, a centrally placed air tube through said end plate, external insulator means around said air tube, a pair of electrical contact points on the periphery of said insulator means and electric wires through said cover plate from said contact points to said heating coil in said Pitot tube, a plurality of spaced apart and projecting L-shaped legs from the outer face of said end cover plate adapted to provide a rapid engagement with a separate mounting section in turn adapted to be connected to a vehicle body, said mounting section having spaced cut-out portions and adjacent lip portions whereby to receive and hold said projecting legs from said end cover plate of said Pitot tube section, a central air tube socket means mounted across the mid portion of said mounting section with an external tube connector means therefrom, and a pair of electric terminals in said socket means positioned to be in alignment and contact with said pair of electric contact points on said insulator means around the air tube from said Pitot tube section.

2. The Pitot tube assembly of claim 1 further characterized in that a spring biased locking pin is provided to project outwardly from the face of the mounting section and a recessed hole is provided within a flange portion from the cover plate of the Pitot tube section at a location to provide proper alignment between the two sections after their engagement.

3. The Pitot tube assembly of claim 1 further characterized in that an extension tube means from said air stream transmitting tube is provided projecting from said insulator means on the cover plate of said Pitot tube section and a slide fit recess portion is provided in said socket means to accommodate said extension tube means, while tubular air stream transmitting means to tube connector means on said socket means is positioned therein to abut the outer end of said extension tube means and carry air stream pressure therefrom.

References Cited UNITED STATES PATENTS 2,204,367 6/1940 Kollsman 73212 3,125,880 3/1964 Oliveau 73-212 3,163,040 12/1964 Werner 73-212 3,428,270. 2/1969 Knight et al 73212 XR FOREIGN PATENTS 464,474 4/ 1950 Canada.

RICHARD C. QUEISSER, Primary Examiner J. K. LUNSFORD, Assistant Examiner 

